Grapevine plant named ‘Mara Seedless’

ABSTRACT

A new and distinct variety of grapevine is provided which abundantly forms attactive medium-to-large seedless berries having a rose-pink skin coloration in medium-to-large clusters. The fruit displays a sweet crisp flavor and is firm in texture. The fruit commonly is ready for harvest during October in the San Joaquin Valley of Central California, U.S.A., and displays good eating qualities as a table grape. The fruit firmness renders the fruit well amenable for handling, shipping, and storage.

Botanical/commercial classification: Vitis vinifera/Grapevine.

Varietal denomination: cv. Mara Seedless.

Background of the New Variety

New grapevine varieties are being sought which display a combination ofoutstanding characteristics in areas such as vigor, productivity, andresistance to diseases and pests. Characteristics such as fruit size,coloration, flavor, taste, and seedless nature of the fruit, also are ofimportance when evaluating new varieties of grape plants.

The new variety of Vitis vinifera was created by artificial pollinationduring the course of a grapevine breeding program wherein two parentswere crossed which previously had been studied in the hope that theywould contribute the desired characteristics. Such breeding program wasinitiated during 1992 near Delano in the San Joaquin Valley of CentralCalifornia, U.S.A. The cross that resulted in the creation of the newvariety of the present invention was made in 1993. The female parent(i.e. the seed parent) of the new variety was the ‘Red Globe’ seededgrape variety (U.S. Plant Pat. No. 4,787). The male parent (i.e. thepollen parent) of the new variety was the ‘Crimson’ seedless grapevariety (non-patented in the United States). The ‘Crimson’ male parentwas released by the U.S.D.A. at Fresno, Calif. U.S.A., during 1989 andwas formed by the cross of the ‘Emperor’ variety (non-patented in theUnited States) and an unreleased seedling named ‘C33-1-99’ (non-patentedin the United States).

The parentage of the new variety can be summarized as follows:‘Red Globe’×‘Crimson’.

The seeds resulting from the above pollination were sown and 210 smallseedling plants were obtained which were physically and biologicallydifferent from each other. The resulting seedling plants were evaluatedin detail and the new variety of the present invention was selected andwas initially designated as R22-V188 and ‘ACS V(26-30) R25R’.

It was found that the new grapevine of the present invention possessesthe following combination of characteristics:

-   -   (a) forms attractive medium-to-large seedless berries having a        rose-pink skin coloration in medium-to-large clusters which        display a sweet crisp flavor,    -   (b) commonly bears fruit during the month of October in the San        Joaquin Valley of Central California, U.S.A., and    -   (c) bears fruit that is firm and is well amenable for storage,        handling, and shipping.

The new variety during observations to date has displayed no visibledisease, and has displayed an ability to well resist cold, drought, heatand wind. The fruit of the new variety has been found to displayexcellent handling and shipping qualities combined with desirabledessert eating qualities.

The new variety of the present invention can be readily distinguishedfrom its ancestors. More specifically, the ‘Red Globe’ parent formslarge clusters of berries which possess seeds, and the ‘Crimson’ varietyforms smaller berries which display lesser rose pink coloration whichalso is less uniform in its presentation.

The new variety of the present invention has been found to undergoasexual propagation beginning in 2000 near Delano in the San JoaquinValley of Central California, U.S.A. by grafting on mature ‘ThompsonSeedless’ rootstock (non-patented in the United States). Such asexualpropagation has been conducted thereafter in successive years through2006, and has shown that the characteristics of the new variety arestrictly transmissible from one generation to another. Accordingly, thenew variety undergoes asexual propagation in a true to type manner.

The new variety has been named ‘Mara Seedless’.

BRIEF DESCRIPTION OF THE PHOTOGRAPH

The accompanying photograph shows as nearly true as it is reasonablypossible to make in color illustration of this character typicalspecimens of the new variety. The photograph includes a typical clusterof the attractive grapes, upper and under surfaces of the leaves, andberries that are transversely and longitudinally sectioned in order toreveal the flesh which lacks seeds.

Dimensions in centimeters are shown at the top of the photograph forcomparative purposes.

DETAILED DESCRIPTION

The chart used in the identification of colors is the Dictionary ofColor by A. Maerz and M. Rea Paul (1930). Common color terms are to beaccorded their ordinary dictionary significance. The description isbased on the observation of plants growing on ‘Thompson Seedless’rootstock outdoors near San Joaquin Valley of Central California, U.S.A.

-   Vine:    -   -   Vigor.—Exceeds that of its ‘Red Globe’ and ‘Crimson’            parental varieties.        -   Productive capacity.—Very productive.        -   Trunk.—Slender, includes long split strips, and six years            after grafting the diameter commonly is approximately 2.4            inches (approximately 62 mm) measured 1 foot above the            ground.        -   Bark color.—Brown (7-E-A), and Chicle Sarouk (7-E-8)            underbark.        -   Cane length.—Medium, and commonly approximately 5 to 6 feet            (approximately 1.5 to 1.8 m).        -   Cane width.—Medium, and commonly approximately 0.5 inch            (approximately 13 mm) at node.        -   Nodes.—Generally round in configuration, and commonly spaced            at a distance of 3 to 4 inches (approximately 76 to 102 mm).        -   Shoot configuration.—Substantially circular to slightly            flattened, approximately 0.8 mm in diameter, and with            longitudinal striations.        -   Shoot color.—Light green (30-D-3).        -   Shoot texture.—Smooth.        -   Growing tip.—Generally ascends straight up.        -   Tendril length.—Commonly approximately 4 to 6 inches            (approximately 102 to 152 mm).        -   Tendril form.—Bifurcated and trifurcated.        -   Tendril texture.—Smooth.        -   Bud shape.—Pointed conical.        -   Bud length.—Commonly approximately 6 mm.        -   Bud width.—Commonly approximately 5 mm.        -   Bud break.—Commonly at the end of March or early April at            the specified location.-   Leaves:    -   -   Size.—Generally medium.        -   Density.—Heavy.        -   Length.—Approximately 4.5 inches (approximately 114 mm) on            average for a mature leaf.        -   Width.—Approximately 4.7 inches (approximately 120 mm) on            average for a mature leaf.        -   Color.—Green (23-J-11) Cossack green on the dorsal surface,            and light green (22-G-5) on the ventral surface.        -   Texture.—Glabrous on the ventral surface.        -   Petiole length.—Commonly approximately 3.3 to 4.8 inches            (approximately 84 to 123 mm).        -   Petiole diameter.—Commonly approximately 4 mm.        -   Petiole sinus.—U-shaped, and occasionally overlapping.        -   Petiole color.—Light green (23-L-1) Holly green.        -   Lobe.—Five-pointed.        -   Color midrib.—Grape green (21-K-7).        -   Margins.—Serrate with irregular teeth, commonly            approximately 10 to 12 teeth per lobe, and approximately 50            to 60 teeth on entire leaf.-   Flowers:    -   -   Date of bloom.—Early May at the specified location.        -   Date of full bloom.—Commonly third week of May at the            specified location.        -   Type.—Fertile.        -   Location.—Primarily at the second or third node from the            base on a spur.        -   Petals.—Five in number, and open from the bottom to the top.        -   Sepals.—Five in number, and commonly poorly developed.        -   Stamen.—Six in number, and upright and diverging.        -   Pollen.—Abundant, and yellow (9-L-4) Sunflower dandelion in            coloration.        -   Pistil.—One in number, and produces a liquid to hold pollen            to achieve germination.        -   Filaments.—Approximately 4 mm in length, and green (22-L-5)            Cerro green in coloration.-   Fruit:    -   -   Time.—Commonly ripe for commercial harvesting and shipment            during early- to mid-October at the specified location.        -   Berry size.—Medium to large.        -   Berry form.—Uniform.        -   Berry shape.—Ellipsoidal elongated.        -   Berry length.—Commonly approximately 1.2 inches            (approximately 30 mm).        -   Berry width.—Commonly approximately 0.7 inch (approximately            18 mm).        -   Berry number.—Commonly approximately 100 to 120 per cluster            on average.        -   Berry weight.—Commonly approximately 6 grams on average.        -   Cluster form.—Commonly conical shouldered, and compact.        -   Cluster size.—Medium to large.        -   Cluster length.—Commonly approximately 8 to 10 inches            (approximately 204 to 254 mm) on average.        -   Cluster weight.—Commonly approximately 500 to 700 grams on            average.        -   Solids.—Approximately 18 percent sugar on Sep. 25, 2006.        -   Acidity.—Approximately 0.37 percent tritrable acidity.        -   Sugar/acid ratio.—Approximately 49.5.        -   Juice pH.—approximately 3.81.        -   Seeds.—Seedless, with an occasional few small traces of            seeds.        -   Capstem.—Strong with long chalaza and attached to vascular            tissue.        -   Pedicel.—Approximately 0.3 inch (approximately 7 mm) in            length.        -   Skin thickness.—Relatively thick.        -   Skin texture.—Very firm.        -   Skin cracking.—No tendency to crack.        -   Skin color.—Rose pink (5-J-3).        -   Lenticels.—None visible.        -   Flesh color.—Light green (21-C-1).        -   Flavor.—Sweet and crisp.        -   Eating quality.—Good and meaty.        -   Use.—Dessert, table grape.        -   Keeping quality.—Very good, after one month in storage,            still displays good appearance.-   Development:    -   -   Resistance to diseases.—No disease problem has been            observed.        -   Resistance to cold.—Good.        -   Resistance to drought.—Good.        -   Resistance to heat.—Good.        -   Resistance to wind.—Good.        -   Shipping and handling.—Excellent.

To further characterize the new ‘Mara Seedless’ variety DNA wasextracted from dried leaf samples and DNA profiles were obtained at thePlant Identification Laboratory of the University of California, Davis,Calif., U.S.A., using base pairs for 10 standard microsatellite DNAmarkers. The data is presented hereafter. Those six markers indicated byan asterisk (*) have been adopted by the European Grape GeneticResources Working Group and Foundation Plant Services as common markersto facilitate the exchange of data among grape research laboratories.

Microsatellite Allele Sizes DNA Marker in Base Pairs VVS2* 135 151VVMD5* 228 238 VVMD7* 239 239 VVMD27* 181 194 VrZAG62* 189 189 VrZAG79*247 259 VVMD6 214 214 VVMD28 247 261 VVMD31 212 212 VVMD32 253 273

The ‘Mara Seedless’ variety has not been observed under all possibleenvironmental conditions to date. Accordingly, it is possible that thephenotypic expression may vary somewhat with changes in light intensityand duration, cultural practices, and other environmental conditions.

1. A new distinct grape plant characterized by the following combinationof characteristics: (a) forms attractive medium-to-large seedlessberries having a rose-pink skin coloration in medium-to-large clusterswhich display a sweet crisp flavor, (b) commonly bears fruit during themonth of October in the San Joaquin Valley of Central California,U.S.A., and (c) bears fruit that is firm and is well amenable forstorage, handling, and shipping; substantially as herein shown anddescribed.